Air conditioner



FIG. 1 is a perspective view of an air conditioner showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a plan view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a right side view thereof, a left side view being symmetrical to the right side view.

The broken lines depict portions of the air conditioner that form no part of claimed design. 

The ornamental design for an air conditioner, as shown and described. 